1. Introduction, Ethics and Methods Flashcards
What is tested on in biopsychology?
human participants and non-human subjects.
What are the advantages of animal research?
-brain and behaviour of other animals simpler than humans.
-comparative approach studying: how having different biological systems can allow for different cognitive abilities.
-allows for research that is not ethical for humans
What are the disadvantages of animal research?
-humans are more efficient subjects (faster to learn, cheaper).
-using humans is the best way to understand humans.
-ethical reasons.
What are the 3Rs of animal experimentation?
reduction, refinement, replacement
reduction
techniques that satisfy the researchers goals whilst inflicting the minimum amount of harm. the minimum amount of subjects used.
refinement
striving to refine techniques to maximise the balance between potential benefits and minimising harm.
replacement
only using invasive techniques if non or less invasive techniques do not exist (development of non invasive techniques should always be worked towards).
Current UK Law - Animals (Scientific Procedures) Act 1986
- strict regulation of all research involving vertebrates as well as cot ephalopods (e.g octopus).
- banned all research on great apes.
- research on other primates along with dogs, cats and horses can only be authorised of no other animal (such as mice) is able to be used.
- UK law seen as Gold Standard in this area and rolled out across the EU in 2013.
personal license
given to individuals allowing them to perform approved procedures within the research programme
How many levels of licensing is there in animal research
3
establishment license
for the entire institution
project license
cover the administration of the specific research programme
Contrast X-ray
- substance that absorbs x-rays is injected
into a compartment of the brain. - improves the contrast between the injected compartment and surrounding tissue.
Cerebral Angiography
- Radio-opaque dye is infused via the cerebral
artery. - This enables the identification of vascular damage.
- Displaced blood vessels can also indicate the location of potential tumours.
X-ray Computed Tomography (CT-Scan)
- X-Ray tubes and detectors rotate around the head and produce many individual x-ray photographs of a brain section.
- Generally the process is repeated for 8-9 sections and a computer-generated 3-D picture of the brain is produced
Magnetic Resonance Imaging (MRI)
- Hydrogen atoms produce distinct waves when exposed to a
magnetic field. - High resolution images are produced by measuring these waves.
- Can be used to construct both 2-D and 3-D images.
Positron emission tomography (PET-Scan)
- radioactive markers are injected into the carotid artery
- cannot be metabolised therefore accumulate in active neurons.
- a map of the brain is produced.
PET pros
- Produces functional brain images.
- Not as susceptible to motion artefacts as fMRI.
- Looking at actual biomechanical process.
PET cons
- Lower spatial resolution than fMRI
- Poor temporal resolution
- Very expensive
- Limited number of scans per subject due to radiation
Functional Magnetic Resonance Imaging (fMRI)
Measures changes in up blood oxygen level dependent (BOLD) response. This is a proxy for energy used by brain cells.
fMRI pros
No injections needed.
- Structural and functional information is present in the same image.
- Better spatial resolution.
- Can produce whole-brain information.
fMRI cons
- Hard to interpret.
- Poor temporal resolution.
Diffusion Tensor Imaging (DTI)
- A variation of MRI based on mapping the
diffusion of water molecules within the brain. - Allows production of images of the major tracts within the brain.
- Allows the study of neural connections within the brain.
DTI pros
- no limitation on imaging depth
- can determine degeneration, lesions and damage of axons
DTI cons
sensitive to noise
Functioning Near Infrared Spectroscopy (fNIRS)
- fNIRS measurements are carried out by transmitting NIR light onto the scalp and using the spectrum of reflect light to detect blood oxygen levels (BOLD).
- Has limited spatial scope compared to fMRI.
- But is much less sensitive to movement artifacts.
- Allows for wireless portable brain imaging.
Skin conductance responses
- Our skin conducts electricity and this can change in
response to emotional changes. - SCR are the most commonly used indicator of changes in skin conductance.
- An increase in SCR is usually associated with emotional thoughts and experiences.
Electroencephalography (EEG)
- Scalp electrodes can record the electrical
activity of the brain. - Changes in electrical activity in response to some event can be inferred by computing the signal-to-noise ratio.
EEG pros
- High temporal resolution (ms)
- Mobile, can remain in natural environment.
- Affordable.
EEG cons
- Measures deeper activity poorly
- Poor spatial Resolution due to tissue distortion.
- Lengthy and difficult preparation.
- Signal: noise ratio is poor
Magnetoencephalography (MEG)
- Records magnetic fields produced by electrical
currents in the brain. - Can analyse either the sensor data (magnetic field) or the underlying currents that generated the magnetic field (estimated currents).
MEG pros
- High Temporal Resolution (ms)
- Magnetic field passes through tissues undistorted.
- Better spatial resolution than EEG
MEG cons
- mostly cortical
- poor
Why do we use multimodal approaches?
Brain stimulation
Electrophysiological recording
Lesions: Aspiration? Radiofrequency? Knife cuts? Reversible lesions?
Why is interpreting lesions difficult?
Transcranial Magnetic Stimulation (TMS)
Transcranial Direct Current Stimulation (TDCS)
General approaches?
Types of tests?
Species typical behaviour?
Semi-natural paradigms?
